Although the approach of explicitly modeling the relation improves the segmentation results, isolating high-level relation features from low-level ones may not strengthen relation propagation, subsequently there is a vanishing-gradient problem [1]}.
The appropriate distance or neighbour count parameter to use in the KNN-based networks [2]}, [3]}, [4]} is often obtained via trial-and-error, which is saturated at a certain number of neighbours and even drastically drops by increasing the number of neighbours or neighbourhood radius. This aspect of such networks is not favorable, especially in dense 3D models.
